Standard kernel compilation produces the following warning: net/core/rtnetlink.c: In function ‘rtnl_newlink’: net/core/rtnetlink.c:3232:1: warning: the frame size of 1288 bytes is larger than 1024 bytes [-Wframe-larger-than=] } ^
This should not really be an issue, as rtnl_newlink() stack is generally quite shallow. Fix the warning by allocating attributes with kmalloc() in a wrapper and passing it down to rtnl_newlink(), avoiding complexities on error paths. Alternatively we could kmalloc() some structure within rtnl_newlink(), slave attributes look like a good candidate. In practice it adds to already rather high complexity and length of the function. Signed-off-by: Jakub Kicinski <[email protected]> --- net/core/rtnetlink.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 8cbdc8398b8c..1699f8540d58 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -2971,14 +2971,13 @@ static int rtnl_group_changelink(const struct sk_buff *skb, return 0; } -static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, - struct netlink_ext_ack *extack) +static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, + struct nlattr **attr, struct netlink_ext_ack *extack) { struct nlattr *slave_attr[RTNL_SLAVE_MAX_TYPE + 1]; unsigned char name_assign_type = NET_NAME_USER; struct nlattr *linkinfo[IFLA_INFO_MAX + 1]; const struct rtnl_link_ops *m_ops = NULL; - struct nlattr *attr[RTNL_MAX_TYPE + 1]; struct net_device *master_dev = NULL; struct net *net = sock_net(skb->sk); const struct rtnl_link_ops *ops; @@ -3226,6 +3225,21 @@ static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, goto out; } +static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct nlattr **attr; + int ret; + + attr = kmalloc_array(RTNL_MAX_TYPE + 1, sizeof(*attr), GFP_KERNEL); + if (!attr) + return -ENOMEM; + + ret = __rtnl_newlink(skb, nlh, attr, extack); + kfree(attr); + return ret; +} + static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr *nlh, struct netlink_ext_ack *extack) { -- 2.17.1
